106 MEMOIRS ON THE COLEOPTERA 



Thoracic base transverse, the median part never projecting posteriorly 

 further than the angles, the latter sometimes obliquely acute and 

 prominent subposteriorly 2 



Thoracic base broadly truncate medially, becoming anteriorly oblique 

 at each side to the angles, which are always minute and inconspic- 

 uous 3 



2 Pronotum never carinate medially; elytra with transverse and more 

 or less close-set rugae Group I 



Pronotum always longitudinally tumid and carinate medially, the elytra 

 more convex as a rule, never having transverse ruga? Group II 



3 Body very variable in form and sculpture but with the pronotum 

 never carinate and the elytra never transversely rugose, rather 

 convex as in group II Group III 



These groups in reality have the nature of subgenera; if they are 

 ever so designated the second will take the name Philolithus Lac. 



Group I Type agrotus Lee. 



Elytra with the inner of the two discal costae wholly obsolete and not 

 even traceable, the second costa ending posteriorly in an acute 

 prominence. Black, opaque throughout and glabrous, the elytral 

 rugae more shining; head broadly impressed, finely, sparsely punctate, 

 the antennae nearly as in the preceding genus, almost as long as the 

 prothorax, the latter about as long as wide, not quite three-fifths 

 as wide as the elytra, inflated and with the sides strongly and evenly 

 rounded anteriorly, narrowing thence with broadly sinuate sides 

 to the basal angles, which are obliquely acute and prominent; base 

 posteriorly sinuate toward the angles; apex moderately sinuate, the 

 angles obtusely prominent and very feebly subeverted; surface 

 feebly convex, closely and rather coarsely punctate medially, though 

 finely punctate apically, becoming broadly concave, coarsely and 

 densely punctate laterally, nearly smooth along the edge, which is but 

 feebly and obtusely subcrenulate, thick and very sensibly and broadly 

 reflexed; elytra oval, widest at the middle, with rounded sides and 

 broadly rounded humeri, the basal margin not prominent laterally; 

 apex rather narrowly produced and lobiform; surface nearly flat, the 

 rugae strong, well separated, disappearing on the apical lobe, the 

 discal costa ending at the summit of the declivity, the marginal carina 

 strong, curving inward rather abruptly behind for a short distance 

 and rapidly disappearing; abdomen with sparse and even punctures, 

 which are moderately coarse and deeply perforate; legs very long, 

 slender, the tarsi long, the claws very well developed, the tibiae and 

 tarsi hispid with very small stiff setae. Length 17.018.0 mm. ; width 



8.75 mm. Lower California (Cape San Lucas) aegrotus Lee. 



A Similar to cegrotus but larger, deep black, less opaque, the elytral 

 rugae shining; prothorax distinctly wider than long, nearly three- 

 fourths (cf ) to three-fifths ( 9 ) as wide as the elytra, flatter me- 

 dially than in the preceding species, with the punctures somewhat 

 small and sparse, finer anteriorly, the surface very broadly and 



